FreeBSD/Linux Kernel Cross Reference
sys/kern/vfs_init.c
1 /* $NetBSD: vfs_init.c,v 1.25 2004/03/23 13:22:05 junyoung Exp $ */
2
3 /*-
4 * Copyright (c) 1998, 2000 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
9 * NASA Ames Research Center.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 * notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 * notice, this list of conditions and the following disclaimer in the
18 * documentation and/or other materials provided with the distribution.
19 * 3. All advertising materials mentioning features or use of this software
20 * must display the following acknowledgement:
21 * This product includes software developed by the NetBSD
22 * Foundation, Inc. and its contributors.
23 * 4. Neither the name of The NetBSD Foundation nor the names of its
24 * contributors may be used to endorse or promote products derived
25 * from this software without specific prior written permission.
26 *
27 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
28 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
29 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
30 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
31 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
32 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
33 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
34 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
35 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
36 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
37 * POSSIBILITY OF SUCH DAMAGE.
38 */
39
40 /*
41 * Copyright (c) 1989, 1993
42 * The Regents of the University of California. All rights reserved.
43 *
44 * This code is derived from software contributed
45 * to Berkeley by John Heidemann of the UCLA Ficus project.
46 *
47 * Source: * @(#)i405_init.c 2.10 92/04/27 UCLA Ficus project
48 *
49 * Redistribution and use in source and binary forms, with or without
50 * modification, are permitted provided that the following conditions
51 * are met:
52 * 1. Redistributions of source code must retain the above copyright
53 * notice, this list of conditions and the following disclaimer.
54 * 2. Redistributions in binary form must reproduce the above copyright
55 * notice, this list of conditions and the following disclaimer in the
56 * documentation and/or other materials provided with the distribution.
57 * 3. Neither the name of the University nor the names of its contributors
58 * may be used to endorse or promote products derived from this software
59 * without specific prior written permission.
60 *
61 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
62 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
63 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
64 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
65 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
66 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
67 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
68 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
69 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
70 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
71 * SUCH DAMAGE.
72 *
73 * @(#)vfs_init.c 8.5 (Berkeley) 5/11/95
74 */
75
76 #include <sys/cdefs.h>
77 __KERNEL_RCSID(0, "$NetBSD: vfs_init.c,v 1.25 2004/03/23 13:22:05 junyoung Exp $");
78
79 #include <sys/param.h>
80 #include <sys/mount.h>
81 #include <sys/time.h>
82 #include <sys/vnode.h>
83 #include <sys/stat.h>
84 #include <sys/namei.h>
85 #include <sys/ucred.h>
86 #include <sys/buf.h>
87 #include <sys/errno.h>
88 #include <sys/malloc.h>
89 #include <sys/systm.h>
90
91 /*
92 * Sigh, such primitive tools are these...
93 */
94 #if 0
95 #define DODEBUG(A) A
96 #else
97 #define DODEBUG(A)
98 #endif
99
100 /*
101 * The global list of vnode operations.
102 */
103 extern const struct vnodeop_desc * const vfs_op_descs[];
104
105 /*
106 * These vnodeopv_descs are listed here because they are not
107 * associated with any particular file system, and thus cannot
108 * be initialized by vfs_attach().
109 */
110 extern const struct vnodeopv_desc dead_vnodeop_opv_desc;
111 extern const struct vnodeopv_desc fifo_vnodeop_opv_desc;
112 extern const struct vnodeopv_desc spec_vnodeop_opv_desc;
113 extern const struct vnodeopv_desc sync_vnodeop_opv_desc;
114
115 const struct vnodeopv_desc * const vfs_special_vnodeopv_descs[] = {
116 &dead_vnodeop_opv_desc,
117 &fifo_vnodeop_opv_desc,
118 &spec_vnodeop_opv_desc,
119 &sync_vnodeop_opv_desc,
120 NULL,
121 };
122
123 /*
124 * This code doesn't work if the defn is **vnodop_defns with cc.
125 * The problem is because of the compiler sometimes putting in an
126 * extra level of indirection for arrays. It's an interesting
127 * "feature" of C.
128 */
129 typedef int (*PFI)(void *);
130
131 static void vfs_opv_init_explicit(const struct vnodeopv_desc *);
132 static void vfs_opv_init_default(const struct vnodeopv_desc *);
133 #ifdef DEBUG
134 static void vfs_op_check(void);
135 #endif
136
137 /*
138 * A miscellaneous routine.
139 * A generic "default" routine that just returns an error.
140 */
141 /*ARGSUSED*/
142 int
143 vn_default_error(v)
144 void *v;
145 {
146
147 return (EOPNOTSUPP);
148 }
149
150 /*
151 * vfs_init.c
152 *
153 * Allocate and fill in operations vectors.
154 *
155 * An undocumented feature of this approach to defining operations is that
156 * there can be multiple entries in vfs_opv_descs for the same operations
157 * vector. This allows third parties to extend the set of operations
158 * supported by another layer in a binary compatibile way. For example,
159 * assume that NFS needed to be modified to support Ficus. NFS has an entry
160 * (probably nfs_vnopdeop_decls) declaring all the operations NFS supports by
161 * default. Ficus could add another entry (ficus_nfs_vnodeop_decl_entensions)
162 * listing those new operations Ficus adds to NFS, all without modifying the
163 * NFS code. (Of couse, the OTW NFS protocol still needs to be munged, but
164 * that is a(whole)nother story.) This is a feature.
165 */
166
167 /*
168 * Init the vector, if it needs it.
169 * Also handle backwards compatibility.
170 */
171 static void
172 vfs_opv_init_explicit(vfs_opv_desc)
173 const struct vnodeopv_desc *vfs_opv_desc;
174 {
175 int (**opv_desc_vector)(void *);
176 const struct vnodeopv_entry_desc *opve_descp;
177
178 opv_desc_vector = *(vfs_opv_desc->opv_desc_vector_p);
179
180 for (opve_descp = vfs_opv_desc->opv_desc_ops;
181 opve_descp->opve_op;
182 opve_descp++) {
183 /*
184 * Sanity check: is this operation listed
185 * in the list of operations? We check this
186 * by seeing if its offset is zero. Since
187 * the default routine should always be listed
188 * first, it should be the only one with a zero
189 * offset. Any other operation with a zero
190 * offset is probably not listed in
191 * vfs_op_descs, and so is probably an error.
192 *
193 * A panic here means the layer programmer
194 * has committed the all-too common bug
195 * of adding a new operation to the layer's
196 * list of vnode operations but
197 * not adding the operation to the system-wide
198 * list of supported operations.
199 */
200 if (opve_descp->opve_op->vdesc_offset == 0 &&
201 opve_descp->opve_op->vdesc_offset != VOFFSET(vop_default)) {
202 printf("operation %s not listed in %s.\n",
203 opve_descp->opve_op->vdesc_name, "vfs_op_descs");
204 panic ("vfs_opv_init: bad operation");
205 }
206
207 /*
208 * Fill in this entry.
209 */
210 opv_desc_vector[opve_descp->opve_op->vdesc_offset] =
211 opve_descp->opve_impl;
212 }
213 }
214
215 static void
216 vfs_opv_init_default(vfs_opv_desc)
217 const struct vnodeopv_desc *vfs_opv_desc;
218 {
219 int j;
220 int (**opv_desc_vector)(void *);
221
222 opv_desc_vector = *(vfs_opv_desc->opv_desc_vector_p);
223
224 /*
225 * Force every operations vector to have a default routine.
226 */
227 if (opv_desc_vector[VOFFSET(vop_default)] == NULL)
228 panic("vfs_opv_init: operation vector without default routine.");
229
230 for (j = 0; j < VNODE_OPS_COUNT; j++)
231 if (opv_desc_vector[j] == NULL)
232 opv_desc_vector[j] =
233 opv_desc_vector[VOFFSET(vop_default)];
234 }
235
236 void
237 vfs_opv_init(vopvdpp)
238 const struct vnodeopv_desc * const *vopvdpp;
239 {
240 int (**opv_desc_vector)(void *);
241 int i;
242
243 /*
244 * Allocate the vectors.
245 */
246 for (i = 0; vopvdpp[i] != NULL; i++) {
247 /* XXX - shouldn't be M_VNODE */
248 opv_desc_vector =
249 malloc(VNODE_OPS_COUNT * sizeof(PFI), M_VNODE, M_WAITOK);
250 memset(opv_desc_vector, 0, VNODE_OPS_COUNT * sizeof(PFI));
251 *(vopvdpp[i]->opv_desc_vector_p) = opv_desc_vector;
252 DODEBUG(printf("vector at %p allocated\n",
253 opv_desc_vector_p));
254 }
255
256 /*
257 * ...and fill them in.
258 */
259 for (i = 0; vopvdpp[i] != NULL; i++)
260 vfs_opv_init_explicit(vopvdpp[i]);
261
262 /*
263 * Finally, go back and replace unfilled routines
264 * with their default.
265 */
266 for (i = 0; vopvdpp[i] != NULL; i++)
267 vfs_opv_init_default(vopvdpp[i]);
268 }
269
270 void
271 vfs_opv_free(vopvdpp)
272 const struct vnodeopv_desc * const *vopvdpp;
273 {
274 int i;
275
276 /*
277 * Free the vectors allocated in vfs_opv_init().
278 */
279 for (i = 0; vopvdpp[i] != NULL; i++) {
280 /* XXX - shouldn't be M_VNODE */
281 free(*(vopvdpp[i]->opv_desc_vector_p), M_VNODE);
282 *(vopvdpp[i]->opv_desc_vector_p) = NULL;
283 }
284 }
285
286 #ifdef DEBUG
287 static void
288 vfs_op_check()
289 {
290 int i;
291
292 DODEBUG(printf("Vnode_interface_init.\n"));
293
294 /*
295 * Check offset of each op.
296 */
297 for (i = 0; vfs_op_descs[i]; i++) {
298 if (vfs_op_descs[i]->vdesc_offset != i)
299 panic("vfs_op_check: vfs_op_desc[] offset mismatch");
300 }
301
302 if (i != VNODE_OPS_COUNT) {
303 panic("vfs_op_check: vnode ops count mismatch (%d != %d)",
304 i, VNODE_OPS_COUNT);
305 }
306
307 DODEBUG(printf ("vfs_opv_numops=%d\n", VNODE_OPS_COUNT));
308 }
309 #endif /* DEBUG */
310
311 /*
312 * Routines having to do with the management of the vnode table.
313 */
314 struct vattr va_null;
315
316 /*
317 * Initialize the vnode structures and initialize each file system type.
318 */
319 void
320 vfsinit()
321 {
322 extern struct vfsops * const vfs_list_initial[];
323 int i;
324
325 /*
326 * Initialize the namei pathname buffer pool and cache.
327 */
328 pool_init(&pnbuf_pool, MAXPATHLEN, 0, 0, 0, "pnbufpl",
329 &pool_allocator_nointr);
330 pool_cache_init(&pnbuf_cache, &pnbuf_pool, NULL, NULL, NULL);
331
332 /*
333 * Initialize the vnode table
334 */
335 vntblinit();
336
337 /*
338 * Initialize the vnode name cache
339 */
340 nchinit();
341
342 #ifdef DEBUG
343 /*
344 * Check the list of vnode operations.
345 */
346 vfs_op_check();
347 #endif
348
349 /*
350 * Initialize the special vnode operations.
351 */
352 vfs_opv_init(vfs_special_vnodeopv_descs);
353
354 /*
355 * Establish each file system which was statically
356 * included in the kernel.
357 */
358 vattr_null(&va_null);
359 for (i = 0; vfs_list_initial[i] != NULL; i++) {
360 if (vfs_attach(vfs_list_initial[i])) {
361 printf("multiple `%s' file systems",
362 vfs_list_initial[i]->vfs_name);
363 panic("vfsinit");
364 }
365 }
366 }
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